Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

const regex = /-i(.*?)-filter/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('-i(.*?)-filter', 'gm') const str = `plex 24029 33.3 3.4 330284 63656 ? Sl 22:37 6:01 /volume1/@appstore/Plex Media Server/Plex Transcoder -codec:0 mpeg2video -codec:1 ac3 -i /volume1/video/classic/Now We've Seen It All!.1976.avi -filter_complex [0:0]yadif[0];[0]scale=w=768:h=576[1];[1]format=pix_fmts=yuv420p|nv12[2] -filter_complex [0:1] aresample=async=1:ocl='stereo':osr=48000[3] -map [2] -metadata:s:0 language=eng -codec:0 libx264 -crf:0 16 -maxrate:0 7752k -bufsize:0 15504k -r:0 25 -preset:0 veryfast -x264opts:0 subme=1:me_range=4:rc_lookahead=10:me=hex:8x8dct=0:partitions=none -force_key_frames:0 expr:gte(t,0+n_forced*5) -map [3] -metadata:s:1 language=rus -codec:1 aac -b:1 256k -segment_format mpegts -f ssegment -individual_header_trailer 0 -segment_time 5 -segment_start_number 0 -segment_copyts 1 -segment_time_delta 0.0625 -segment_list http://127.0.0.1:32400/video/:/transcode/session/vgh38cdsdmd70euan70xdqh8/cf3a3188-52f9-4b26-8b63-1c348a7c9348/seglist -segment_list_type csv -segment_list_size 2147483647 -segment_list_separate_stream_times 1 -max_delay 5000000 -avoid_negative_ts disabled -map_metadata -1 -map_chapters -1 media-%05d.ts -start_at_zero -copyts -vsync cfr -y -nostats -loglevel quiet -loglevel_plex error -progressurl http://127.0.0.1:32400/video/:/transcode/session/vgh38cdsdmd70euan70xdqh8/cf3a3188-52f9-4b26-8b63-1c348a7c9348/progress`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions